Device for testing the imbalance of balance wheels

ABSTRACT

A device for testing, finding and eliminating any imbalance of a rotary body such as a balance wheel of watches and clocks having various elements to measure imbalance and equilibrate the body to its desired correct balance. The device includes measuring means, correction tools, drilling means, brake structure and means to transport the bodies through the various corrective and measuring stages.

United States Patent Jahnetal.

[151 3,667,326 ['4 June6,1972

m N E M m an n A m m m n N U Q U m m mm M mm T0 RE a E M mB Pm m [72]Inventors: Paul Jahn, Schramberg; Alfred Kapp,

2 55 I I577 ww 1 m n" n e" "nob" bzsmm dh omow C K 6220 456 9999 HHHU724 3 ,m 0872 8883 ,25 222 Schramberg-Sulgen, both of Germany [73]Assignee: Gebruder Junghans G.m.b.ll.,' Schramberg,

Wurttemberg, Germany [22] Filed! 1967 Primary Examiner-Francis Husar I211 App] 724 ArtorneyWatson, Cole, Grindle & Watson ABSTRACT A devicefor testing, finding and eliminating any imbalance of a rotary body suchas a balance wheel of watches and clocks having various elements tomeasure imbalance and equilibrate 408/16 193/12 the body to its desiredcorrect balance. The device includes 823!) 49/00 measuring means,correction tools, drilling means, brake '77/5; 193/12 13 structure andmeans to transport the bodies through the various corrective andmeasuring stages.

m l 4 b 3 2 B 52 s11 lnt.Cl............. [58] Field 1 Claim, 17 DrawingFigures P ATENTEDJUH 6 I972 SHEET 3 OF 7 PATENTEUJUN 6 I972 SHEET 8 OF 7v Fig. 16

DEVICE FOR TESTING THE IMBALANCE F BALANCE WHEELS This invention relatesto a device for the finding and eliminating of the imbalance of adisk-shaped rotating body with a small gyrating mass, preferably of abalance wheel, with a measuring device in which the body that is to beequilibrated is placed in rotation and a changing mechanical valueoccurring during the rotation. As a result of the imbalance, it isconverted into an electrical value whose amplitude serves as a measurefor the value of the imbalance that is to be corrected and its phaserelation for the determination of the place at which the correction,correcting the imbalance, is to be made. A tool is provided for theelimination of the imbalance, for example, a drilling device, and abraking device is provided which is triggered by said electrical value,released after the measuring value has been obtained for the value ofthe imbalance at the time of a certain phase relation of the electricalvalue produced, and which promptly arrests the body that is to beequilibrated and which rotates at the test speed in a suitable positionin front of the tool in order to eliminate the imbalance.

A device of this type is known and in the case of this device, it isnecessary to place the body, that is to be equilibrated, by hand intothe measuring device and remove it again from said device after theoperation.

The present invention is based on the feature to develop the knowndevice in such a manner that it will operate to a large extentautomatically. At the same time, while being of a simple structure, thedevice is to operate reliably and is supposed to take into account allsorts of possibilities, so that it can be used for individualmeasurements and for equilibration of individual bodies, in addition tobe used in mass production. This will be achieved, according to theinvention, by providing a transportation arrangement moving the bodies,which are to be equilibrated, into the measuring device, in that themeasuring arrangement contains a holding arrangement for the bodies thatare to be equilibrated, in that a take-over device has been providedcarrying away the bodies that are to be equilibrated from the measuringdevice and in that a control arrangement has been provided influencingthe transporting device and/or the holding device, and being influencedby the measuring device. I

At the same time, a storage place, receiving several bodies that are tobe equilibrated can be assigned to the transportation arrangement, whichpreferably is exchangeable. The holding device comprises preferably tworadially closed bearings, receiving the axis of the body that is to beequilibrated, which are arranged on two arms mounted swivelably, in theplane of the axis. A friction wheel, which is connected with a drive,can be assigned to the measuring device holding the body that is to beequilibrated, which friction wheel can be brought into frictionalcontact with the body that is to be equilibrated.

The control arrangement comprises preferably a trailing or servo-controldevice for rising and falling DC electric current, which will both limitthe work path of the tool and releases the stop of the body that is tobe equilibrated. A cam disk can be provided for limiting of the workpath of the tool with which the servo-control device is only connectedpositively in the adjusting direction, whereby a holding device,operable by the control arrangement, is assigned to the cam disk.Preferably, the servo-control device and the cam disk are connected withone another by means of a spring.

For the release of the brake device for the bodies that are to beequilibrated, a switching device operable by the servo-controlarrangement can be provided. Preferably, this switching device comprisesa contact arranged on a swivelably mounted arm, to which is assigned astationary contact, whereby a cam disk driven by the servo-control hasbeen provided, which cam disk keeps the contacts separated from oneanother in the rest position of the servo-control device, and whereby anarm has been provided which is in frictional contact with the cam diskand which has been connected with the swiveling arm, and

which seeks to bring about a closing of the contacts in the case of theadjustment movement of the servo-control device. Preferably in thiscase, the cam disk is provided with a cam which is adjustable in theperipheral direction.

Furthermore, the control arrangement preferably contains a cam shaftdriven by a transportation motor, for the drive of control linkages forthe operation of the holding device, the take-over device and thedriving arrangement for the test body.

Further objects will be apparent from the following description whenconsidered in connection with the accompanying drawings in which: 7

FIG. 1' is a perspective view of an apparatus for balancing the balancebody according to the invention;

FIG. 2 is a perspective view of the measuring device with its holdingarrangement;

FIG. 3 is a side elevation of a magazine for the balance wheels to bemeasured; I

FIG. 4 is a top plan view of the magazine partly in section taken online lV-IV of FIG. 3 in the direction of the arrows;

FIG. 5 is a side view of a part of the magazine according to FIG. 3;

FIG. 6 is a plan view of a detail as viewed in the direction of thearrow of FIG. 5;

FIG. 7 is a plan view of the feed lock according to FIG. 6;

FIG. 8 is a perspective view of a modified magazine;

FIG. 9 is a side view of the take-off device;

FIG. 10 is a plan view of'the device of FIG. 9;

FIGS. 11 to 15 are side views partly .in section showing the controlcams;

FIG. 16 is a diagrammatic view of the complete control elements andconnections; and

FIG. 17 is a graphic diagram showing three different balance bodies.

1 The reference numbers 10 and I1 designate two guide rails in FIG. 1,which serve for the feed in of balance wheel bodies to the measuringdevice. In FIG. 1, the rails 10 and II have a balance wheel body 12therebetween, which is held in the rails 10 and 11 by the lock '36,which will be explained. After release of the lock 36, the balance wheelbody reaches the measuring device designated in FIG. 2 in a generalmanner by 13, in which measuring device the balance wheel shaft isreceived by the bearings 44 and 45.

After carrying out the equilibrating process, the balance wheel 12' isreleased and drops into the take off arrangement designated by 14, whichhas been shown in more detail in FIGS. 9and l0.

A motor 15 has been provided for the drive of the balance wheel 12',which drives a friction wheel 17 by a belt 16, which friction wheel ismounted in a lever 18. This lever 18 is mounted swivelably on an axleand it can be moved up and down with the aid of a cam shaft 19, as aresult of which the friction wheel 17 can be brought into frictionalcontact with the balance wheel 12' and can be moved away from thelatter.

The measuring device has been designated in FIG. 2 in a general mannerby 13. It contains two arms 42 and 43 which carry at one end the twobearings 44 and 45. The arms 42 and 43 have been attached to twocarriers 52 and 53 with the aid of pliable lamellae 50 and 51.Furthermore, a counterpoise 47 has been attached to the arms 42 and 43,which has been connected by way of a cross arm 47a and by likewisepliable lamellae with the arms 42 and 43. One of these pliable lamellaehas been designated in FIG. 2 with the reference number 46. By means ofthe connection of the measuring device 13 with the carriers 52 and 53with the aid of pliable lamellae, thismeasuring device is swivelablearound an axis which is in parallel to the balance wheel shaft. Besidethat, each of the two arms 42 and 43 can be swiveled around aperpendicular axis, as a result of which the bearings 44 and 45 can bemoved in a horizontal plane receiving the balance wheel shaft.

The movement of the arms 42 and 43 is brought about with the aid of pegs40 and 41, which have been arranged on two toggle levers 37 and 38,which are swivelable around one perpendicular axle 39 each. The freeends of the levers 37 and 38 are connected with the swivelably mountedlever 24 by a rod 25, which lever at its free end carries a roller 24acooperating with a cam 22.

In order that the arms 42 and 43 with their bearings 44 and 45 canseizea balance wheel 12 moved out of the guide rails 10 and 11, agripping device 56 has been arranged at-the end of the'guide rails 10and 1 1, which is swivelable around an axis 57. The swiveling movementtakes place by means of a rod 55, which in turn is connected with aswivelably mounted lever 26 by a rod 27, which lever at its free endcarries a roller 26a cooperating with the cam 23. The gripping device 56can be swiveled with the aid of the cam 23 into the position shown inabroken line in FIG. 1, in which position this device holds the balancewheel 12' in a position in which it can be seized by the bearings 44 and45.

The lever 18 consists of the two parts 180 and 181 which can be swiveledhead on around the peg 29. The two lever parts 18a and 18b are held bythe spring 30 in the position shown in FIG. 1.

' For the purpose of swiveling the lever part 18b around the peg 29, arotary magnet 31 has been provided which is connected by a tie rod 32with the lever part 18b. In this manner it is possible to place thefriction wheel 17 in frictional connection with the balance wheel 12,independently of theposition of the cam 21.

The lock 36, which holds the balance wheel body located between theguide rails 10 and 11, consists, as can be seen in FIGS. to 7, of twoangular arms 36a and 36b which have been fixedly arranged on the shaft33. This shaft, at its free ends, carries a rod 35 which rests upon thelever part 18b carrying the friction wheel 17. By the spiral spring 34,the rod 35 is pressed against the lever part 1812. In case this leverpart 18b is lifted, then the rod 35 is swiveled upwards and thus thearms 36a and 36b, as shown in FIG. 7, are swiveled to the left. In thecase of swiveling these arms 36a and 36b, the balance wheel, held in thelock, will be released in the middle position of these arms and it rollsbetween the guide rails and 11 in the direction of the measuring device13.

The shaft 19 which carries the earns 21 and 23 is driven by atransporting motor designed with the reference number 20 in FIG. 16. Theoperation of the various arrangements is brought about by the cam disks21 and 23, arranged on the shaft 19, by the above mentioned rod systems.In FIGS. 1 1 to the various operating processes, which are brought aboutby the cams, are shown in detail. The operating position shown in FIG. 1corresponds to the cam position shown in FIG. 12. The shaft 19 is drivenby the transporting motor in the direction of the arrows shown in FIGS.12 to 15, as a result of which the rollers 180, 24a and 26a, assigned tothe cams, are lifted up or lowered corresponding to the shape of thecams. The various positions of the rollers 18c with regard to the cam 21are indicated in FIG. 11. In actual fact, the roller 18c naturally doesnot assume the positions A to E as shown, rather the cam 21 rotates inthe direction of the arrow and the roller is either lifted or loweredcorresponding to the presentations in FIGS. 12 to 15.

Starting out from position A in FIG. 11, the cam 21 moves in thedirection of the arrow around the angle 01. During this rotationalangle, the friction wheel 17 is in contact with the balance wheel 12'.In the subsequent rotation around the angle B, the roller 18c and thusthe lever part 18b is lifted up, as a result of which the friction wheel17 is lifted off the balance wheel 12. In the case of a further rotationof the cam 21, the roller 18c reaches the position E by the position D,in which former position the rod 35 of the locking device 33, 36 alsolifted up together with the lever part 18b far enough, so that thelocking arms 36a and 36b in FIG. 7 will be swiveled to the left, as aresult of which, in the middle position of the arms 36a and 36b, theforemost of the balance wheel bodies located lever part 18b, the arm 36aof the locking device again arrives between the guide rails 10 and 11,while the arm 36 b is again moved on, as a result of which the foremostbalance wheel body again reaches the position shown in FIG. 1.

In the case of the rotation of the shaft 19, the rod 25 is operated bythe cam disk 22 in such a manner that the arms 42 and 43 are moved at asuitable movement for the reception of a new balance wheel and for therelease of an equilibrated balance wheel.

Through the cam disk 23, during this time, that is to say during therelease of a new balance wheel, the catching device is swung into theposition drawn in a broken line FIG. 1, as a result of which the balancewheel is caught within the area of the bearings 44 and 45. H

In the case of nonnal operation, the shaft will revolve from position Ainto position C FIG. 11, in which the transporting engine or motor 20,-driving the shaft 19, FIG. 16, is switched off by a contact driven byitself. The equilibration of the balance wheel is accomplished in thisposition.

If the imbalance has not yet been eliminated at the first working, or ifa control measurement is to take place after this working, then it willbe necessary to drivethe balance wheel 12' once more. Since the cam 21isat a standstill, the part 18b of the lever is swung around the peg 29with the aid of the ro tary magnet 31, so that the friction wheel 17comes into frictional contact with the balance wheel 12.

After elimination of the imbalance, the transport engine 20 is switchedon again, as a result thereof the shaft 19 continues to turn until itreaches the position shown in FIG. 13, in which between the guide rails10 and 11 will bereleased. Then the I next following balance wheel bodyis held firmly by the arm 36b. In the case of the subsequent downwardmovement of the the roller 24a is lifted by the cam 22, as a result ofwhich the ends of the arms 42 and 43 carrying the bearings 44 and 45 aremoved apart and thus release the balance wheel. In the case of a furtherrotation of the shaft 19, the roller 260 will be lifted by the cam 23and thus the catching device 56 is brought into the position drawn in abroken line in FIG. 1. In the case of a further rotation of the shaft19, the latter assumes the position as shown in FIG. 14, in which, asdescribed previously, the locking device 36 is released and thus a newbalance wheel body is moved into the measuring arrangement 13. In thecase of the position of the shaft 19 according to FIG. 15, the roller24a has been lifted up by the cam 22, as a result of which the pegs 40and 41 are moved outward. Thus, the arms 42 and 43 have been released,as a result of which the shaft of the newly fed-in balance wheel hasbeen received by the bearings 44 and 45. The method of operation will beexplained in more detail later on in connection with FIG. 16.

The balance wheel bodies 12 fed to the device by means of the guiderails 10 and 11 are preferably'taken from a storage space, which, forexample, is exchangeable. Such a storage space can be developed indifferent ways corresponding to the types of balance wheels that are tobe received. In FIGS. 3 to 5 a storage space has been shown which issuited particularly for balance wheel bodies consisting of one disk,while a storage space has been shown in FIG. 8 which is providedpreferably for double disk storage spaces for balance wheel bodies.

The storage space shown in FIGS. 3 to 5 consists of a base plate 70 onwhich two perpendicular carrier plates 71 and 72 have been arranged. Inthese carrier plates 71 and 72, recesses pointing in an outwarddirection have been provided, in which guide rails 73 and 76 are held.These guide rails are wound spiral fashion. Two guide rails each, namelythe guide rails 73 and 74 as well as the guide rails 75 and 76 form ascrew thread. The guide rails have been developed U-shaped and the guiderails forming a screw thread face each other with their open sides. Thedisks of the balance wheel bodies are held by these guide rails. Thestorage place has been closed on top by a plate 77, in which openings 78and 79 have been provided through which the storage space can be filledwith balance wheel bodies.

In the lower part of the storage space the levers 80 and 81 have beenprovided, which have been mounted swivelably and which carry at one endfingers 80a and 81a. These fingers 80a and 81a mesh throughcorresponding perforations in thev guide rails 74 and 76 with saidrails, so that the exit of the storage space is locked.

The two free ends 80b and 81b of the levers 80 and 81 rest upon the baseplate 70, which contains perforations 82 and 83 within the reach ofthese lever ends 801; and 81b.

The storage box is placed on a corresponding plate 61 of the deviceaccording to the invention, FIG. 5. This carrier plate has a bolt 85onto which the storage box is placed with one of its perforations 82 and83. As a result thereof, the proper lever end 80b and 81b is lifted up,thereby pulling out the oppositely located lever end 80a or 81a from thecorresponding guide rail, as a result of which the exit from the storagebox is released or opened.

As can be seen particularly in FIG. 3, the storage box represents adouble threaded screw. In the case of the storage space shown in FIG. 5,one of the screw threads is connected with the guide rails and 11, whilethe other screw thread, formed by the guide rails 75 and 76, has beenclosed by the lever 80 or its end 80a. If the screw thread formed by therails 73 and 74 is empty, then the storage box is lifted off the plate61 and is rotated 180, as a result of which the end of the screw threads75 and 76 now establishes contact with the entrance of the guide rails10 and 11 and the lever end 80b is lifted by the bolt 85, as a result ofwhich the connection between the rails 75 and 76 and 10 and 1 1 isestablished.

FIG. 8 shows a plate-type storage place which contains a fixed baseplate 90, which has been placed onto the carrier plate 61 of the device.The base plate 90 contains an annular groove 90a in which the disks ofthe balance wheel bodies 12 lie. The base plate contains, furthermore, aslot 9012 running in a radial direction, through which always onebalance wheel body can reach the guide rails 10 and 11, passing throughthe carrier plate 61.

A rotatable part 92 has been arranged above the base plate 90, which hasbeen subdivided by intermediate walls 920 into sector-shapedcompartments. This rotatable part 92 is driven by a step-by-step motor93, in such a manner that at each drive phase one balance wheel body 12is brought into the area of the slot 90b.

In FIGS. 9 and 10, the take off device, FIG. 1, with its rails 14 hasbeen shown in more detail. These rails are held by a holder 95. Aseparate piece of rail 14 has been inserted in one of the rails 14,which separate piece is connected, for example, with a rotary magnet 97.With the aid of this rotary magnet 97, it will be possible to swing thepiece of rail 14' from the position shown in FIG. 9 into the positionshown in FIG. 10, in which it runs parallel to a further piece of rail96. In this way it will be possible to eliminate individual balancewheel bodies, for example, such as those that cannot be equilibrated.

The method of operation of the device according to the invention willnow be described in detail on the basis of FIG. 16.

By operation of the switch 149, the transport engine 20 driving thecontrol shaft 19, FIG. 1, is switched on by means of the relay 148. As aresult thereof and as explained previously, a balance wheel body 12' isguided to the measuring device 13 or balancing scale, and the frictionwheel 17, FIG. 1, is brought into frictional contact with the body ofthe balance wheel. The motor 15, driving the friction wheel 17, isswitched on simultaneously with the transport motor 20. A control disk134 has been arranged on the shaft 15a driven by the motor 15, whichswitches off the motor 15 again by a switch or a relay 136. Thetransport motor too is switched off again by means of a switch which hasnot been shown and which is controlled by the motor itself.

After switching off of the motor 15 and after removal of the frictionwheel 17 from the balance wheel body 12, the latter will run out freely,as a result of which the measuring device 13 is placed into vibrations,becoming even stronger, which are converted into electrical voltagevariations by the condenser 100. These voltage variations are fed to ahigh frequency carrier circuit 101, high frequency oscillator anddemodulater stage. The low frequency on the output side is fed to anamplifier 103 by means of a relay 102 or a flip-flop circuit, the

output of said amplifier being indicated by a measuring instrument 104.On the measuring instrument 104 one will thus be able to read the valueof the imbalance.

The output of the amplifier 103 is furthermore guided to a rectifier105, whose output voltage is filtered by the stage 106. This smootheddirect current voltage is fed to an amplifier 108 by a phase producer107, the output of said amplifier being used for the control of aservomotor 109 with the windings 110 and 1 11. A potentiometer 112 isdriven by the shaft 113, driven by the motor 109, said potentiometerbeing connected with the phase producer 107. The elements 107 to 112represent a servo-operated control for a rising and falling DC current,which is controlled by the voltage produced by the balance wheel 12. Theangle of rotation of the motor 109 is therefore proportional to themagnitude of the imbalance.

The shaft 113 carries at its end a disk 117 with a peg 117a, againstwhich a lever 120 rests, which is connected with the shaft 119, and thisshaft is driven in the same measure during the adjusting movement of themotor 109. A cam disk 121 has been arranged on the shaft 119, whichcooperates with a lever 127 mounted swivelably on the axis 126. Theposition of the lever is determined by the position of the cam 121. Thislever 127 acts as a stop for a collar arranged on the spindle 140 of thetool, so that by the adjustment of thelever 127, which corresponds tothe magnitude of the imbalance, the operating depth of the tool 58 willbe limited.

Furthermore, a disk 122 has been arranged on the shaft 1 19 which can beheld firmly with the aid of a magnet 123. Therefore, the shaft 1 19 canbe arrested in a certain position, while the shaft 113, after havingreached a certain angular position, can again return to the zeroposition, whereby the spring 118, connecting the disk '17 with the shaft17a, is cocked. After releasing or after denergizing the magnet 123, itwill then be possible for the shaft 1 19 to return again into its restposition.

Another disk 1 14 has been arranged on the shaft 113, which carries acam 114a adjustable in the peripheral direction. Beside the disk 114, alever 116 has been mounted swivelably on an axis 115. This lever 116carries a pointed pin 116b, which rests on the cam 1140. Furthermore, alever 116 has an arm 116a which rests with its free end 116b on theperiphery of the disk 1 14. In case of an adjusting movement of themotor 109, the disk 114 revolves in the direction of the arrow V, as aresult of which the pointed pin 116b is lifted off the cam 114a. In thecase of the return movement of the motor 109, on the other hand, thedisk is moved in the direction of the arrow R, as a result of which thelever 116 too is moved in this direction. If the adjusting movement ofthe motor 109 has been so small that the cam 114a did not move away fromunder the pointed pin 1 16b, then in the case of a return adjustment ofthe motor, the pointed pin 116b will again touch the cam 114a, so thatthe lever 116 will again assume the position of FIG. 16. If, however,the adjusting movement of the motor 109 has been so great that the cam 114a has moved away from under the pointed pin 116 then the lever in thecase of the return adjusting movement will not be stopped by the cam114a, but will be moved further to the right, as a result of which thecontact 116a, located on the lever 116, will touch the stationarycontact 150. As a result thereof, the thyratron 131 is switched on,which prepares the thyratron 130 for a switching step. Without such apreparation, the thyratron cannot be fired or switched by the impulsearriving from the impulse delayer 129.

In the following, three methods of operation, corresponding to threedifferent balance wheel bodies with varying imbalance values; FIG. 17,will be explained.

In the case of a balance wheel body with a very small imbalance, whichis still located within a permissible area (Example 1 in FIG. 17), themethod takes place in the manner as already described, that is, first ofall, the motors l5 and 20 are placed in motion and are switched ofiagain by automatically controlled switches, while the vibrations of themeasuring device are converted into corresponding electric voltageswhich bring about the adjustment of the lever 127. Because of the smallimbalance, the angle of rotation of the motor 109 is so small that thepointed pin 116b does not leave the area of the cam 1 14a. It is nowexplained that the area of tolerance is adjustable with the aid of thiscam 1140. Naturally, it is also possible, in a reverse manner, to changethe area of tolerance in an electric way by the adjustment of the zeropoint of the servomotor. Since in the present case the pointed pin doesnot leave the area of the cam 114a, the contact 116a, 150 will not beclosed either in the case of untwisting of the motor, and thus thethyratron 131 is not fired. Thus a firing of the thyratron 130 is notpossible either.

Besides, the delaying relay 137 has been excited by the relay 102, thedelay time of the former being somewhat longer than the time requiredfor the adjustment and resetting of the servomotor 109. Since a firingof the thyratron 130 does not take place, the transport motor 20 isswitched on by this relay 137, as a result of .which and by means of thecontrol shaft 19, FIG. 1, the balance wheel is released by the measuringdevice, while a new balance wheel is placed into the measuring device13.

In the case of a balance wheel with an imbalance value corresponding tothe second example in FIG. 17, the adjustment of the lever 127 isaccomplished in the same way as in the first case. However, theadjusting motor has revolved at such an angle that the pointed pin 1 16bis no longer within the area of the cam 1 14a. In the case of resettingof the disk 114, the contact 116a, 150 will thus be closed, as a resultof which the thyratron 131 is fired and the thyratron 130 is prepared.The latter will then be fired through the next impulse arriving from theimpulse retarder 129, as a result of which the magnet 123 is energized,which stops, by the disk 122, the shaft 119 and thus also the lever 127,while the shaft 113 is able to return into the zero position whereby, asalready mentioned, the spring 1 18 is cocked. The magnet 132, whichoperates the braking arrangement 59 for the body of the balance wheel12, is energized simultaneously with the magnet 123. As a resultthereof, the balance wheel will be stopped in such a position in frontof thetool 58, that the imbalance can be eliminated by this tool.Through the excitation of the relay 138, the driving motor 139 isswitched on and thus the tool is placed in motion, whose working depthis limited by the lever in connection with the collar 141.

Besides, the delay relay 137 has been deenergized by the thyratron 130by the relay 102 so that a renewed switching on of the transport motor20 cannot be accomplished.

A second shaft 142, which carries two control disks 143 and 144, isdriven by the motor 139 which operates the tool 58. After the shaft 142reaches a certain angle of rotation, the balance wheel-driving motor isswitched on for the purpose of a remeasurement of the balance wheel bodytreated, by the control disk 144 by relay 145. At the same time, thelever part 18b is deviated by the rotary magnet 31, shown in FIG. 1, andthus the friction wheel 17 is brought into frictional contact with thebalance wheel body 12.

The contact 1460 is opened for a brief time by the control disk 143 bythe relay 146, so that the thyratron 130 is switched ofi". As a resultthereof, the magnet 123 is deenergized and thus the shaft 119 isreleased, which moves back upon the action of the spring 118, until thelever 120 again touches the peg 117a. Beside that, the braking device132, 59 is deenergized and the motor 139 is switched ofi.

If the remeasurement shows that the remaining imbalance lies below thelimit a, FIG. 17 then the transport motor 20, as described in connectionwith the first example, will be switched on and the balance wheel willbe released from the measuring device 13.

If the balance wheel body has a very large imbalance, corresponding tothe third example in FIG. 17, then an equilibration in one operationprocess will not be possible. Then, following the first work process andas explained in connection with the second example in FIG. 17, a secondwork process will take place, and, if need be, even a third such workprocess until the imbalance has dropped below the limit a in FIG. 17.

Besides, the circuit contains four switches I to IV, which can beoperated by hand, and with which one will be able to adjust differentmodes of operation. The following modes of operation are possible:

1. Switch I open: In this case the servo-control is switched off and onecan make a simple measurement or a control of the imbalance.

2. Switch 11 open: In this switching position it will be possible tomeasure the imbalance for the the purpose of calibrating the device andthe body that is tobe equilibrated can be clamped down firmly, and thusthe position of the center of the mass can be indicated.

3. Switch IV open: In the case of this position of the switch, theimbalance is measured, .the adjusting device is operated, the balancewheel is slowed down and clamped down, and subsequently the balancewheel is worked in order to eliminate the imbalance, whereupon aremeasurement takes place after each working. This method of operationhas been described in connection with the third example in FIG. 17.

4. Switch III open: In the case of this method of operation, theimbalance is measured, the adjusting device is operated, the balancewheel is slowed down and clamped firmly and subsequently the balancewheel body is worked, whereby a remeasurement will be made only in sucha case whenever the imbalance surpasses a certain value.

In the case of the operating method 4 (Switch III open), noremeasurement takes place within the range a to b, FIG. 17. In the caseof a value of the imbalance according to the second example in FIG. 17,the method takes its course just as in the operating method 3, asdescribed. Switching on of the transport motor 20 takes place by thecontrol disk 144, the relay 145 and the relays 147 and 148, since theswitch III is open. The relay 147 will be acted upon by the relay 125,which'in turn is switched in dependence on the angle or rotation of theshaft 119, and thus on the value of the imbalance of the balance wheelbody 12. If the imbalance surpasses a certain value, namely theborderline b in FIG. 17, then the relay 147 will be influenced by therelay 125, as a result of which, as already mentioned, switching on ofthe motor 15 will be accomplished; if the imbalance is below the borderline b, then the relay will not be operated and in that case thetransport motor 20 will be switched on by the relay and the relay 147,and thus the balance wheel will be released from the measuring device 13without remeasurement.

In the case of the device described, a cam disk 114 is used for thesetting of the range of tolerance. Naturally it is also possible to useother devices instead of the cam disk 114 for the adjustment of therange of tolerance, for example, an electronic arrangement whichoperates on the basis of a condenser discharge.

We claim:

1. Device for determination and elimination of the imbalance of arotatory body with a slight gyrating mass, preferably a balance wheelcomprising a holding device for the rotatory body, a measuring means fordetermining the value and the position of the imbalance, a tool for theelimination of the imbalance such as a drilling device with a brakingdevice which arrests the rotatory body that is to be equilibrated in asuitable position before the tool for the elimination of the imbalance,transportation means to move the body that is to be equilibrated intothe measuring means and moving it out again therefrom, and control meansfor the braking device influenced by the measuring means, the tool andthe transportation means as well as the holding device, at the same timethe control means containing a follower control for a rising and fallingDC voltage consisting of an adjusting motor fed by an amplifier, a phasetransmitter to control said amplifier and being influenced by a DCcurrent signal discharged by the measuring means and is influenced by asecond signal which is supplied by a potentiometer arranged on the shaftof the adjusting motor, a shaft having a cam means of the braking meansfor the body that is to be equalized, said switching means beingoperated in dependence on the rotational direction and on the magnitudeof the rotational angle of said adjusting motor and a further motordriving said tool.

1. Device for determination and elimination of the imbalance of arotatory body with a slight gyrating mass, preferably a balance wheelcomprising a holding device for the rotatory body, a measuring means fordetermining the value and the position of the imbalance, a tool for theelimination of the imbalance such as a drilling device with a brakingdevice which arrests the rotatory body that is to be equilibrated in asuitable position before the tool for the elimination of the imbalance,transportation means to move the body that is to be equilibrated intothe measuring means and moving it out again therefrom, and control meansfor the braking device influenced by the measuring means, the tool andthe transportation means as well as the holding device, at the same timethe control means containing a follower control for a rising and fallingDC voltage consisting of an adjusting motor fed by an amplifier, a phasetransmitter to control said amplifier and being influenced by a DCcurrent signal discharged by the measuring means and is influenced by asecond signal which is supplied by a potentiometer arranged on the shaftof the adjusting motor, a shaft having a cam mounted thereon for theadjustment of a stop member limiting the feed path of the tool and whichis connected with a shaft of the adjusting motor by a return spring andis coupled rigidly with said shaft in only one direction, a holdingmeans for the shaft on which the adjusting cam for the stop member ismounted, and switching means for switching on the holding means of thebraking means for the body that is to be equalized, said switching meansbeing operated in dependence on the Rotational direction and on themagnitude of the rotational angle of said adjusting motor and a furthermotor driving said tool.